The world is reeling from the worst terrorist outrage in history. Four hijacked planes are deliberately crashed causing death and devastation in New York and Washington DC.

Click on the links to watch BBC coverage of events in America.

America's darkest day

Just before 0900EDT in New York an aircraft flew into the north tower of the World Trade Center, minutes later a second plane flew into the south tower. A third plane later ploughed into the Pentagon building in Washington DC.

Some reports say up to 800 people may have died when a third hijacked plane crashed into the Pentagon. The Mayor of Washington has declared a state of emergency in the city. But despite the carnage, the capital city is refusing to be bowed.

The UK's airports, cities and government buildings are on heightened security alert following the terror attacks on the US. All private aircraft have been grounded and no flights allowed on the normally busy flight paths over London until further notice.

The World Trade Center, situated in New York's financial district, was once one of the most potent symbols of the financial might of the United States. It provided one of the most popular postcard views of New York and - along with the Statue of Liberty - symbolised the city to many people.